Hemodialysis is a process by which microscopic toxins are removed from the blood using a filtering membrane such as a dialyzer. Typically, hemodialysis is administered to a patient in periodic three to four hour sessions. Each session takes place two or three times per week. There exists a growing body of research that prefers daily dialysis since increased dialysis time improves outcomes, both in terms of quality of life and patient longevity. An additional number of researchers believe that continuous dialysis for twenty-four hours a day, seven days a week would provide the best outcome for a patient in terms of quality of life and longevity. The actual implementation of substantially continuous dialysis has been impossible to date because of technology and cost constraints. Regardless, it is believed that continuous renal replacement therapy (CRRT) would be an enormous improvement over intermittent dialysis because far more toxins can be removed from the blood using a CRRT device seven days a week and for nearly twenty-four hours a day.
Some advantages of providing CRRT include an expected decrease in morbidity and mortality, a decrease in the amount of medications required, a decrease in fluid intake, a decrease of dietary restrictions, and numerous improvements to the quality of life of the end-stage renal disease (ESRD) patients. Present day CRRT machines are stationary, large, heavy machines adapted to provide dialysis, hemofiltration or a combination of both to individual patients. The existing CRRT are cumbersome and require electrical, connection to 120-140 volt AC electrical outlets as well as several feet of tubing to connect the machine to the patient. In addition, these machines require a continuous supply of gallons of fresh filtered water to create the dialysate fluid. Furthermore, a patient must remain connected to the existing heavy and cumbersome CRRT machine for many hours each day, which limits his or her ability to perform normal, everyday activities.
An additional problem with existing dialysis machines is that frequent reconnection and disconnection to the machine requires accessing blood flow in a patient by puncturing an artiovenous shunt. These shunts only last for limited periods of time and subject the patient to infection, clotting and other complications which result in numerous hospitalizations and repeated surgical interventions. Another problem with existing dialysis machines is as these machines become smaller and a bit more portable, smaller hemofilters or dialyzer filters must be used that does not clog or clot too quickly so that extended or continuous dialysis can be performed. A common type of dialyzer includes nine hundred or more cylindrical hollow fibers through which blood flow is provided. The hundreds of cylindrical hollow fibers are contained in a shell or container in which dialysate fluid is circulated around and past the exterior walls of the hollow fibers. The exterior walls of the hollow fibers or lumens are semi-porous so that impurities in the blood can be moved from the blood and into the dialysate. One problem that occurs in a dialyzer is the clogging or clotting of blood flow within individual hollow fibers. Such clogging of blood flow through the fibers decreases the effectiveness of the dialyzer's filtration and blood cleaning properties. Furthermore, it is understood that proteins and other compounds or substances in the blood may clog the pores of the semi-porous membrane overtime and decrease the effectiveness of the dialyzer filter. If a dialyzer filter is to be in continuous operation twenty-four hours a day, seven days a week, it is important that such a dialyzer be operational for extended periods of time at or near a continued peak performance without becoming clogged or having its efficiency decreased significantly during usage. Furthermore, it would also be useful if a dialyzer remained efficient and effective when a low-power pump is used to pump blood there through such that a minimum amount of energy is required for the highest possible clearance of impurities from a patient's blood at the lowest amount of required energy.
Dialyzers' membranes have been studied for well over a half of a century. The initial inventors of dialysis or dialactic therapy understand the basics of diffusion and how toxins diffuse across a dialyzer's membrane from blood to a dialysate fluid. There are many factors that influence diffusion in solute transfer across a semi-permeable membrane. Such factors have been explained in various prior articles about the workings of a dialyzer. But, again there has been limited or minimal research on providing a dialysis device wherein the dialyzer operates efficiently over extended periods of time (more than 15 hours) in order to provide a low power completely wearable or portable dialysis device having a dialyzer with increased efficiency over that of previous dialysis machines having a dialyzer with a membrane of the same or similar membrane surface area.